Vaginal douching is practiced regularly by approximately 37% of American women, but little is known about the associated risks. The purpose of this investigation is to determine the degree to which douching is an independent risk factor for tubal pregnancy. Additional objectives include: 1) characterizing douching practices by demographic, behavioral and reproductive valuables; 2) assessing the frequency of douching and its timing in relation to menses, sexual intercourse and pregnancy; 3) collecting information on types of douche preparations and technique, as well as reasons for douching; and 4) detecting infection with C. trachomatis as a potential confounder or effect modifier. A multi-center, case-control study will be conducted at six hospitals in Baltimore, Maryland. Cases (n=150) will be women between the ages of 18 and 44 years who are admitted to the obstetrical service with a diagnosis of tubal pregnancy. Concurrent with the selection of cases, two groups of controls will be identified from the participating hospitals and matched to cases on race. The first control group (n=150) will be selected from among women with an intrauterine pregnancy at 20 weeks' gestation or less attending their first prenatal visit. The second control group (n=150) will be selected from among women with a diagnosis of postpartum tubal ligation. I will conduct an in-person interview, collect a blood specimen for chlamydia serology, collect a urine specimen for the detection of C. trachomatis using polymerase chain reaction (PCR), and obtain fallopian tube tissues (from cases and postpartum tubal ligation controls) for PCR detection of C. trachomatis. Fallopian tube tissue will be obtained as paraffinized tissue block from each participating hospital's pathology lab. Analyses will consist of univariate and multivariate techniques, including conditional multiple logistic regression.